Polyethoxy tertiary-alkyl benzoates



United States Patent POLYETHOXY TERTIARY-'ALKYL BENZOATES Joseph F. Coates, Philadelphia, and Robert M. Lincoln,

Media, Pa., assignors to The Atlantic Refining Company, Philadelphia, Pa., a corporation of Pennsylvania No Drawing. Application September 4, 1956 Serial No. 607,549

5 Claims. (Cl. 260-476) This invention relates to low-foaming synthetic nonionic detergents and methods of preparing same. More particularly .this invention relates to polyethoxy monoand poly-tertiary alkyl benzoates, and mixtures of same, wherein the tertiary alkyl group or groups are directly substituted on the benzene ring. I

It is known in the art that non-ionic synthetic detergents of the ethylene oxide condensate type have high detergency-low foam characteristics which make them particularly suitable for home laundry and dishwashing machines, as well as for many industrial purposes. The products of the instant invention possess these characteristics to a superior extent.

It is therefore an object of this invention to produce non-ionic synthetic detergents having superior detergency properties.

It is another object of this invention to produce nonionic synthetic detergents having very low foam characteristics. I

It is another object of this invention to produce synthetic detergents which can be readily and economically spray dried or drum dried with builders to yield a powdered product having the desired high detergency-low foam properties.

Other objects and advantages will become apparent from a reading of the following description and the appended claims.

It has been discovered that the novel non-ionic synthetic detergents of this invention possess high detergency-low foam properties to a superior extent and that when combined with builders they can be readily and economically spray dried or drum dried to form powders. In accordance with the present invention, a benzoic acid having from 1 to 4 nuclear hydrogens substituted by a tertiary alkyl group containing from 4 to 16 carbon atoms, wherein the total number of carbon atoms in'the alkyl substituents ranges from 4 to 16, is condensed with ethylene oxide in the presence of an alkaline catalyst, preferably an alkali metal hydroxide, at a temperature of from approximately 100 C. to 200 C., until the mole ratio of ethylene oxide to the acid is from about 4&1 to about 30:1. Mole ratios of ethylene oxide to acid of 11:1 to 19:1 are preferred, with the best results being obtained when the mole ratio is from 16:1 to 18:1. Although the condensation reaction may be carried out at temperatures ranging between 100 C. and 200 C., it is preferable to carry outthe reaction at temperatures from 140 C. to 180 C.

Instead of producing the ester by condensation of the quantities of polyethylene glycols ranging in average ice molecular weight from about 550m about 1000, with 190 C. in the presence of from about 0.1 weight percent to about 0.5 weight percent of a highly acidic cata lyst such asa sulfonic acid catalyst, xylene sulfonic acid being preferred. Athough the catalyst may be omitted, the reaction time is considerably shortened in its presence.

The polyethoxy monoand poly-tertiary alkyl benzoates thus produced have the general formula Ran-4 R1 R2 wherein R R R and R may be either hydrogen atoms or tertiary alkyl groups. The number of hydrogen atoms should not exceed three and the sum of the carbon atoms in the tertiary alkyl groups should not exceed 16. The value of it may range from about 3 to about 29 V with values from 10 to 18 'being preferred and with values from 15 to- 17 being the most-preferred range. Examples are polyethoxy mono-tertiary butyl benzoate,

polyethoxy di-tertiary butyl benzoate, polyethoxy tri-tertiary butyl benzoate, polyethoxy tertiary octyl benzoate,

polyethoxy mono-tertiary nonyl benzoate, polyethoxy propyl benzoate.

Exceptionally high detergency values have been obtained consistently from the condensation product of ethylene oxide with C alkyl benzoic acid. The acid is prepared by the oxidation of C alkyl toluene. The

latter, in turn, is the alkylation product from the AlClg catalyzed reaction of toluene and diisobutylene.

Ethylene oxide may be added to mono, di, or higher tertiary alkyl benzoic acids or any combination thereof,

to give condensates of good to excellent detergency. 3 The acid is placed in a glass or stainless steel apparatus, cat'alyst added, and the reactor is heated to C. to

C. When the mixture is sufficiently hot and therefore mobile, the passage of ethylene oxide through a disperser such as a sintered glass disc is begun. Addition is slow at first. After the first mole of ethylene oxide has" been added, the rate picks up several fold. It is generallybelieved that ethylene oxide 'adds'to the most acidic function first, and when 'all such acidic functions are con-1 sumed, addition begins on the terminal hydroxyl group,

which is more rapid. The rate of addition also increasesas the temperature rises.

The catalyst used may be any basic catalyst such as KOH, LiOH; NaOI-l, metallic sodiumor a mixture of sodium hydroxide and sodium glycerophosphate. Alkali metal hydroxides are preferred. The catalyst may he added inan aqueous solution or in solid form, but it is preferred to use solid catalysts. About 1 weight percent to about 13 weight percent of the catalyst, based on the acid, may be-used, 1 weight percent to 4 weight percent being preferred.

The final condensation product has a characteristic odor which may be removed by blowing the hot mixture with nitrogen at atmosphericfpressure or under vacuum. An alternative is to steam strip the odor from the hot mix, or to treat with benzene and strip off the latter. 7 -The color in the ,final non-ionics may be reduced or bleached with froml to about 5 volume percent of 30 percent aqueous hydrogen peroxide.

' Patented June 24, 1958' 15% by weight polyethoxytertiaryalkylbenzoate 50% by weight sodium tripolyphosphate 33 by weight sodium sulfate 2% byweight carboxymethyl cellulose The synthetic detergents of this invention may: be. spray dried or drum dried with builders to form powders. In spray drying the built detergents slurry is pumped to the top of a high tower and fed in a series of sprays at a temperature of about 150 F. The droplets, are met by a concurrent stream of high temperature gas at 550 F. to 650 F. inlet and 250. F. to 3-00 F. outlet which evaporates the water from the droplets leaving them in the form of solid detergent particles on falling. Drum drying of the built detergent slurry may be accomplished in conventional equipment using about 100 pounds steam pressurein the drums.

As previously stated, the non-ionic synthetic detergents of theinstantinvention may. also be prepared by directly esterifying the monoand poly-tertiary alkyl benzoic acids with equimolar. quantities of polyethylene glycol. The. polyethylene glycol. may range in; averagev molecular weight from about 550 to about 1000, withthose having an average molecular weight of about 600 being preferred. The esterification temperature may range from approximately 130 C. to approximately 190 C.. The reaction may be carried out with or without a catalyst, but in order to increase the reaction rate it is desirable to employ a highly acidic catalyst such. as' a sulfonic acid catalyst, preferably xylene sulfonic acid, in an amount varying fromabout 0.1 weight percent to about 0.5 weight per cent. The reaction time varies from about 4 hours toabout' 28 hours.

The tertiary alkyl benzoic acids which are condensed with ethylene oxideor esterified with polyethylene glycol to. form the polyethoxy tertiary alkyl benzoates; of the; instant invention may be prepared by known methods,

for example by the oxidation of tertiary alkyl toluene,-

with 'afree oxygen-containing gas in the presence of. a; cobalt naphthenate or manganese naphthenate catalyst. The acids produced by this oxidation step may be used either undistilled or distilled with the distilled acid being preferred. The tertiary alkyl toluene may be a monoor poly-tertiary alkyl toluene or mixtures of same, but it isv preferred to utilize those alkylates having a boilingrange, above mono-tertiary alkyl toluene. The alkylate maybe prepared by conventional methods, for example, by; the; reaction of diisobutylene or propylene polymer with: toluene in the presence of an aluminum, chloride or; boron. trifluoridev catalyst. The diisobutylene is a commercially available chemical. tained commercially or may be manufactured, for example by contacting a. gas stream comprising a major proportion of propylene with a catalyst consisting: of phosphoricacid impregnated on kieselguhr at a temperature of 500 F. to 550 F. and 400 p. s. i., at a rate of'about 01 pound mols of propylene er pound of catalyst per hour and fractionally distilling the resultant mixture' of" propylene polymers to give an overhead fraction. comprising mainly the trimers (C polymers) boiling between approximately 300? F. and 340 F. to 360 1 2, a second" cut boiling up to approximately 465 F; comprising predominantly tetramers (C polymers) and a distillation residue boiling up to about 520 F. and comprising the.

The propylene polymer may be obpentamers (C polymers).

The C polymers are employed' to make the tertiary nonyl alkylates,'whil'e the C polymers are employed to make the tertiary dodecyl alkylates.

The non-ionic detergents were tested in a standard Launderometer apparatus. The procedure and method of calculating detergency values differ in minor details from that shown in Carbon: Soil Removal, P. T. Vitale et a1., Soap and Chemical'Specialties, vol. 32, No. 6, pp. 41-44 (June 1956), and are described below. The Launderometer consists of a spindle rotating in a hot water thermostated bath. Mason jars of 1 pint capacity containing detergent, water, soiled cloth;v and balls for agitation are rotated for a set time at a set rate in the hot water. The'degree of cleaning is determined and the resulting numbers are the detergency values. These values were originally correlated with a standard anionic detergent having anarbitrarily assigned detergency'value and a standard nonionic. detergenthaving an assigned detergency value based on, the standard anionic detergent.

It is known that the nonionic detergents of the prior art exhibit essentially the same detergency and foam characteristics in soft water (less than 100 parts per million hardness)" asin hard-water (over'150200 p. p. m. hardness). In a number of the examples which follow soft water was used in determining the detergency and foam characteristics of the nonionic detergents of the instant V invention, in the remaining examples hard water was used" in the determination. 7 It will be seen, that in both cases the' nonionic detergents of the instant invention were superior in detergency and foam characteristics over the detergents of the prior art.

The detergency tests, are conducted in the following manner I The new cloth is washed with 2 weight percentof a;

commercial mild fatty acid soap. to remove the sizing. It is put through 3 full rinse cycles in an automatic washer,

hung to'damp dry, out into 4 inch wide strips, i'roned'and set in a desiccator in a temperature and humidity controlled room. 7 V

The strips of cloth are soiled with the followingv composition:

homogenizer and the balance of the carbon tetrachloride added; About 200 ml. of soil is placed in a nine inch evaporating, dishand a strip of the cloth is passed through this rapidly and smoothly three times. The cloth is hung to dry at room temperaturefor 2 hoursilS-minutes and is then cut into 2 inch by 4 inch swatches. and read. photometrically.v The photometer is calibrated against, a magnesia block with the standard equal to 100. I

One pint Mason. jars are washed and set in, the Launderometer rack... They are each filled with 6 ml. of 5 percent by. weight solution of the above mentionedbuilt composition, 10 three-eighth inch diameter hard rubber. balls, one soiled swatch, and enough 300 p. p. m. or 30 p. p. in. (hard or sof water, respectively) hardness water. to. make ml. of solution. .The final, concentration of the built composition is 0.3 percent with the concentration of the active polyethoxy,tertiaryialkyl ben zoate, being 0.045 percent by weight. The jars are capped, set on the spindle, and'rotated at 40-42 RIP; M. for 20=minntes at F. The jars are immediately removed, the-heightof the" foam above the detergent" solution ineach jaris immediately noted (following one" The concentrated soil, slurry is then passed through a small, hand-operated quick inversion of each jar), and the swatches are dried on paper and photometer readings taken.

Thedetergency is calculated in the following way.

Preparation of acid A 32,650 g. portion of the pot bottoms from the distil lation of the alkylate having a boiling range above mono- 5 tertiary butyl toluene were charged to a stainless steel Raw Detergency=- X 100=L turbo gas absorber; six percent cobalt naphthenate catalyst in a concentration of 1.5 ml. per 100 gms. of charge Where: was-added. 7 Air was passed in at a rate of 3.1 ml. per R=photometric percent reflectance of the washed cloth minute per of chargereactionwas T' fi S=photometric percent reflectance of the soiled cloth 10 at a temperature of to Watelf and h u-i percent fl ta of the virgin cloth water soluble light organics amounting to 9.85 weight S ua1ly -an e f 18 24 percent based on the charge were condensed from the V is practically a constant at 87 effluent v R varies f 40-80 The oxidation mixture comprising the C to C tertiary alkyl benzoic acids was taken up in 2 volumes of hexane. The L value is then related t a t d d value b a 110 mole percent of 5 percent NaOH solution was used factor to give the final detergency: to extract the'hexane solution. The caustic and hexane solutions were cross washed, and the washes were coms bined with the corresponding phases. 110 mole percent D f HCl was added to the aqueous phase to acidify the base. 'The free organic acid was extracted with benzene and Where: washed with water and dilute caustic. The I-ICl-free S ==th arbitrary detergency of h d d benzene solution was stripped of benzene. The yield L =the L a detergency) valu f th t d d hi h 25 was 33.3 weight percent acid on a no-loss basls based on is always run concurrently with the material being the alkylate. The acids were distilled in several batches tested. to give" a 64.2 weight percent overhead. The bulk of the acids were combined in a composite having the {01 An arbitrary detergency (S of 70 is assigned to a lowing analysis: a commonly used commercial anionicjfdetergent which is employed as the standard. A non-ionic commercial a detergent is used as a secondary standard and is assigned Acid numbe 237 KOH/ 8 1 a detergency of 80 based on the assigned value of 70' Ester number .9.*..... 1020 mg.KOH/gm'. for the standard anionic. Hydroxyl number 12 mg KOH/ gm.

The detergency data obtained by testing various repreb y lpel'centsentative compounds of this invention in the examples I s which follow not only demonstrate the utility of the in g f ffgfig fifig fii fififigfifigggfi theomtical. vention, but also demonstrate the superiority of these com ounds over the standard anionic and non-ionic deterg nts available commercially. 40 Ethylene Qxlde addmqn,

. The composited acids were charged to a stainless steel- EXAMPLE I 1 carbon steel turbo mixer. Two weight percent pulver-' ixed KOH was added and the agitated mixture was heated Prepamnon of alkylate to 170 C. to 175 C. Ethylene oxide was passed into" 552 moles of toluene were charged to a glass. lined ,f the reaction mixture. An induction period of about one; Pfaudler kettle. Two weight percent AlCl were added P was riqmrqd to reach a lzlgmole mm) of ethyl??? and the mixture was heated with agitation to 66 F. 552 oxlde 9 F of reacnon f d t}??? moles of diisobutylene havin an initial boiling point of P so that addltloflal Xter11a1 heatlngwfls r q lr d. 101 C. and a dry point of 105 C., (ASTM D4073) 17.5 moles of ethylene oxide were added per mole of were added at such a rate as to maintain the desired tem-. i charged; v y Was essentially quantitative: perature, external heating being required during the ad- Samples were taken at each mole ratio of ethylene oxide dition of the last 150 moles. The reaction mixture was from 8:1 to 17.5:1 and each of these was compounded into cooled and the catalyst sludge discarded. The alkylate the previously described 15 weight percent active poly- Was. washed successively with water, 1 percent HCl, 4 ethoxy tertiary alkyl benzoate built detergent composipercent NaOH, and water, until neutral. The alkylate tions. Table. II summarizes the detergencies and foam was distilled to give the fractions enumerated in Table I heights at 0.3 percent concentration, in 30 p. p. n. hardwhich were analyzed by the mass spectrometer. ness water, of the built detergent compositions.

TABLE I Grams Weight API Ml. Volume Cut Point Composition Percent Percent Cutl 19,000 18.9 53.0 24,800 20.6 229? Unrcacted. Cut2 40,100 40.0 33.6 47, 000 39.3 92 F Mono-tert-butyl toluene. Bottoms 30,500 39.4 32.2 45,700 38.2 above393? F. 0, to C11 tert-alkyl tnluenes V predominantly Mono-tertoctyl toluene, and Di-tertbutyl toluene. Recovery- 98, 600 98.3 117, 500 7 Charge oss 2 TikBIIE II Moles Ethylene Detergen- Foam RumNumber Oxide per cy at 0.3% Height Mole of 00110. (Inches)- Acid 8 74 0 9 73 0 10 74 0 11 74 0 12 77 0 13 77 0 14 78 0 15 84 0 16 89 0 17. 5 93 0 18 84 3s 20 81 3e 21 82 as 22 81 3e 1 Samples 11 t0'14 were preparedbyadding ethylene oxide to'sample No..10.ln aglassapparatus in the presence of 2 weight "perpentipulverized KOHat a temperature of 170175 C. and were tested inthe same manner as'Samples 1 to 10, inclusive.

These data show clearly the preferred. range. of moli ratios of. ethylene oxide to acid.

EXAMPLE II.

Another portion of the. same acid. mixture used. lIlJEXr ample]; was charged to a: glass reactor in difierent portions. Varying catalysts were employed and. in varying.

tions of benzene: as above and filtered to remove a faint haze. The product at this stage was a bright: lightiamber liquid, ,It'had a-detergency valueofiSS anda foam. height of A; inch in 300 p. p. In. hardness water and a detergency of 85 and a foam height of Ms inch in p. p. to. hardness water at 053 percent concentration of the built formulation described hereinbefore. These data show that the non-ionics of the instant invention have markedly superior detergency and low foamcharacteristics in both hard and soft water.

A distillation fraction from another portion of the acids prepared for this example having a molecular weight of: 233 (predominantly tert octyl benzoic acid) based on an. acid number of 240, was condensed with ethylene oxide in the presence of 2 weight percent pulverized KOH. A totalof 21 moles of ethylene oxide per' mole ofacid were added at a temperature of 160 C. with samples taken at intervals. Table IV sets forth "the detergency values and foam heights at 0.3 percent concentration, in 30 p. p. m. hardness water of the built formulation heretofore described.

TABLE IV MolesEth- Detergeuey Fo m- RunNumber. yleue Oxide at 0.3% Height perM'ole Cone. (Inches) of Acid 8. 0 1L 82 0 17 91 3Q 21- 86 ;a

EXAMPLE IV TABLE III.

Moles Run Ethylene M; W. Temp. Detergency Foam Number Oxide per Acid Catalystt(Wt; Percent) 0.) at 0.3% Height Mole of (Inches) Acid 17.8 236 i 93 0 7 17. 5. 236 17c. 91 as 16.6 236 170 l 86 is; 15.8 236 84 15.9 236 13% KO 81 13.6 236 (2% NaOH, 5% So- 170 86 0- dium Glycerophos- I phate.)

EXAMPLE III 55 based on acid number, was reacted with an equnnolar A 2010 g. quantity of tertiary alkyl benzoic acids ranging from C to C being predominantly tertiary octyl benzoic acid as determined by mass spectometer analysis and having an average molecular weight of 246 based on.

an acid number of 228 were prepared in the manner similar to that described under Example I, using manganese naphthenate instead of cobalt naphthenate as a catalyst, and were charged to a 12 liter glass fiask. Forty grams of pulverized KOl-I were added, the agitated mixture was heated to 170 C. to C. and 17I6molesofethylene. oxide per mole of acid were passed in. On completion: of the reaction the product was blown withnitrogenunden vacuum at a temperature of 104 C. to 126 C. The product was mixed with 1 liter of benzene which was then. stripped 011. This process was repeated 5. times-toreduce odor and remove unreacted: low boiling materials. The color of product at this stage was a clear red; Decolorization was effected by treatment with 3 volume per- The batch was then treated twice more with 1000 ml. porsulfonic acid catalyst.

quantity of commercial poly-ethylene glycol having an average molecular weight of '550. Another portion of the same "acid'was reacted with. an equirnolar quantity of a cornmercia'l polyethylene glycol having anaverage-molecular weight of 600111 thepresence of 021' weighf'percent' of a Xylene sulfonic acid catalyst. A third portion of the acid was reacted with an equimolar quantity of a commercial polyethylene glycol having an average molecular weight of 100.0. A commercial pure monotertiary butyl benzoic acidhavingamolecular weightof 178 was esterh fied with anr-e'quimolar quantity; of: a commercial polyethylene glycol havingv an average molecular weight of 600' in the"presence" of'0i43' weight percent of a xylene V The temperatures of the various reactionsvariedfrom 13.0." C. to C. The reaction periods variedifrom 4 hours to 28 hours, heating being intermittent. The esters made from each run were tested for detergency'and foam height'at 0.3 percent concentration, in-30' p. p..m.;.hardness water, ofi'thebuiltformulaa tron. previously described. The. results. aresetforth-in- Table V.

TABLE V Polyethylene Catalyst 1 Glycol Deter- Foam Run No. Moles (Wt. Per- (Carbowax) Temp. Time gency Height cid cent) 0.) (Hrs) at 0.3% (Inch) Cone. M. W. Moles weight of 240 based on acid number.

* Xylene sultonlo acid. 8 Commercial pure mono-tertiary butyl benzoic acid.

EXAMPLE V An 80.4 gram portion of AlCl was added to a reaction flask containing 2679 ml. of toluene and the mixture was heated to 57 C. with agitation. An 893 ml. portion of a commercial propylene polymer comprising principally monoolefins in the C to C range, and having an approximately distillation range of percent at 355 F. and 95 percent at 385 F., was added to the reaction mix while the temperature was maintained at 57 C. The mix was transferred to a separatory funnel and washed successively with 200 ml. of 1:1 I-ICl, 100 ml. H 0, 100 ml. percent NaOI-I, and 400 ml. H O. The unreacted toluene was stripped off and the alkylate was fractionally distilled. The dodecyl toluene distilled over a boiling range of 168 C. to 195 C. at 20 m. in. pressure, the main portion distilling over a range of 172 C. to 182 C. at 20 m. in. pressure and consisting of about 65 percent to about 70 percent tertiary dodecyl toluene, the remainder being secondary.

A 101 gram portion of this alkylate was oxidized with air in the presence of 1.4 ml; of cobalt naphthenate catalyst at a temperature of 170 C. to 200 C. and 14 ml. of water were collected over a period of 1 hour and 40 minutes. A total of 31.2 grams of acid was recovered which consisted of tertiary dodecyl and higher molecular weight tertiary alkyl benzoic acids. About 14.5 grams of the acid were charged to a glass reactor. Two weight percent pulverized KOH was added and the reaction mix was heated to 170 C. to 175 C. Ethylene oxide was passed in through a sintered glass disc. Samples were taken at various mole ratios of ethylene oxide 7 to acid and each of these was compounded into the previously described 15 Weight percent built detergent compositions. Table VI sets forth the detergencies and foam heights at 0.3 percent concentration in 300 p. p. m. hardness water, of the built detergent compositions.

We claim: 1. Polyethoxy tertiary alkyl benzoates having the general formula wherein R R R and R are each a radical selected from the group consisting of a hydrogen atom and a tertiary alkyl radical containing from 4 to 16 carbon atoms, the number of radicals consisting of a hydrogen atom not exceeding three and the sum of the carbon atoms in the total number of said alkyl groups not exceeding 16, and wherein n has a value of from 10 to 29.

2. The products according to claim 1 in which n has a value of from 10 to 18.

3. The products according to claim 1 in which R is a tertiary octyl radical, R R and R are hydrogen atoms and n has a value of from 10 to 18.

4. The products according to claim 1 in which at least one of the radicals, R R R and R is a tertiary butyl group and the remainder are hydrogen atoms, and wherein n has a value of from 10 to 18.

5. The products according to claim 1 in which R is a tertiary alkyl group consisting of a propylene polymer, R R and R are hydrogen atoms and n has a value of from 10 to 18.

References Cited in thefile of this patent UNITED STATES PATENTS 1,710,424 Loehr Apr. 23, 1929 2,624,752 Morris et a1. Jan. 6, 1953 2,714,607 Matter Aug. 2, 1955 

1. POLYETHOXY TERTIARY ALKYL BENZOATES HAVING THE GENERAL FORMULA
 2. THE PRODUCTS ACCORDING TO CLAIM 1 IN WHICH N HAS A VALUE OF FROM 10 TO
 18. 